The above-mentioned hand-guided work apparatus are known in many forms. In the housing of the work apparatus, an internal combustion engine is provided for driving the work tool. A combustion chamber is formed in a cylinder of the internal combustion engine and this combustion chamber is delimited by a piston which drives a crankshaft in rotation. A spark plug is held in the cylinder which delivers an ignition spark via an ignition module at an ignition time point at a given crankshaft angular position in dependence upon the control. The ignition spark ignites an air/fuel mixture compressed in the combustion chamber to drive the piston. A short circuit line is connected on the ignition module for stopping the ignition. The short circuit line is to be connected to ground for switching off the internal combustion engine.
The short circuit line is, as a rule, connected to ground via a switch, key switch or the like and short circuits the ignition in this way so that the ignition module can no longer trigger any ignition sparks. The internal combustion engine stops operating and comes to standstill.
The development of the drive technology in work apparatus has led to complex ignition modules which not only consider the rpm for determining an ignition time point for the next crankshaft revolution but also other operating parameters such as the temperature of the internal combustion engine, the position of the throttle flap, the pressure in the the crankcase, et cetera. All this additional information must be supplied to the ignition module, so that the latter, while considering the different parameters, can compute the ignition time point of a next crankshaft revolution or read it out of a characteristic diagram.